1. Technical Field
The invention relates to an apparatus for simulating the shear stress which is exerted on particles dispersed in solution, such as, for example, proteins. The invention further relates to a method of determining the shear stress in the components needed for filling (filters, filling needles, pumps, hoses, etc), particularly for filling a liquid that contains dispersed particles (such as biomolecules/proteins/macromolecules). The present invention further comprises the use of a shear stress application (PSA) for simulating shear stress in processing and filling plants for solutions with high molecular components (such as proteins, DNA, antibodies, etc.).
2. Background
In aseptic manufacture, liquid products are generally transferred into so-called primary packaging systems.
On its way from the manufactured product to the primary packaging, the product, which may in some cases be delicate or fragile, passes through numerous industrial processes associated with filling, such as stirring, sterile filtration, pumping, transporting, filling, etc. processes or devices. Each of these processes necessarily includes fluid flows in which shear velocities are produced. These shear velocities represent a mechanical shear stress for the particles dispersed in the solution (e.g. proteins) and may lead to damage or even to the destruction of the product that is to be filled, depending on the strength and stability of the product.
The problem was therefore to provide a process that allows a systematic, reproducible collection of data on the correlation between shear stress and stability of the particles dispersed in the solution.
In order to determine the effects of the various filling processes or of the process as a whole on the stability and quality of the product, a shear stress application was developed and used (e.g. for process control). In addition, it is possible using the application in order to determine product sensitivity in the aqueous system, and thereby assess suitable formulations and facilitate the discovery of suitable formulations.